Riichi Ueshiba is a Japanese manga artist born on September 4, 1969, in Fukuoka Prefecture. He is best known as the original creator of the manga series Yume Tsukai and Nazo no Kanojo X, both of which were adapted into anime television series.

Ueshiba developed an interest in drawing from a young age. After graduating from high school, he enrolled at Waseda University in Tokyo, where he joined the universitys manga research group. While still a student in 1991, he won the general category grand prize in the Comic Open Chiba Tetsuya Award for his entry Discommunication. This winning entry was published in Kodanshas Morning magazine, marking his professional debut as a manga artist. The success of his debut led to a sequel series, also titled Discommunication, which was serialized in Kodanshas Monthly Afternoon magazine beginning in 1992. His demanding work on the series ultimately led him to leave university without graduating.

Ueshibas career is defined by a series of long-running serializations, all published in Monthly Afternoon. Following Discommunication, which ran in various installments until 2000, he created Yume Tsukai, serialized from 2001 to 2004. His most famous work, Nazo no Kanojo X, began as a one-shot in 2004 before becoming a full serial from 2006 to 2014. After a brief hiatus, he returned with Ookumo-chan Flashback, which ran from 2017 to 2020. The English version of Nazo no Kanojo X is published by Vertical, while Discommunication has been released digitally in English by J-Novel Club.

Several of his manga have been adapted into other media. Yume Tsukai was adapted into a twelve-episode anime series produced by Madhouse, which aired in 2006. Nazo no Kanojo X was adapted into a thirteen-episode anime series by Hoods Entertainment in 2012, followed by an original video animation episode. Furthermore, Discommunication was adapted into a radio drama in 1996, and characters from that series made a cameo appearance in the fourteenth OVA episode of Nazo no Kanojo X.

Thematically, Ueshibas work is characterized by a focus on the complexities of love, puberty, and sexuality, often exploring unusual or fetishistic romantic dynamics. His early works, such as Discommunication and Yume Tsukai, are notable for incorporating dense visual references to the mythologies and folklore of India, Southeast Asia, China, and Japan, creating a complex and esoteric atmosphere. Later works, beginning with Nazo no Kanojo X, shifted away from overt mythology to emphasize everyday life and character-driven storytelling, though they retained a core focus on unconventional romance. A well-documented admirer of the band Yellow Magic Orchestra, Ueshiba frequently includes citations and parodies of their work, as well as other manga, anime, and tokusatsu series. He is also known for working without assistants, creating all elements of his manga entirely by himself. His artistic style is noted for its intricate background details, and he often includes a self-representation as a one-eyed cat named Bad Cat within his works.

Ueshibas significance in the industry lies in his unique and consistent artistic vision. He has maintained a loyal following by exploring niche psychological and relational themes within the seinen manga demographic, bridging the gap between surreal, folklore-infused narratives and poignant, unconventional love stories. His reluctance to use social media or follow mainstream trends has contributed to a public persona defined almost entirely by his distinctive body of work.